Method of making dense wall panels



4C-z. ELLIS Filed March 11, 1958 INVENTOR. GEORGE h. LL/.S'

llllll ooaoe. Q

k uw s N HJ.: Wnwa 4 ATTORNEY July 16, 1940.l

vMETHOD 0F MAKING kDENSE WALL PANELS hasta .my 16,1940 i 2,208,511

UNITED STATES PATENT A(y1-*Figli *mamon or MAKING nENsn wmvrams Georgen. Ems, New Brunton, Minn., assigner to vThe Insolite Company,Minneapolis, Minn., a corporation o! Minnesota Application March 11,1938, Serial No. 195,353

'I Claims. `(Cl. 92-39) 'I'his invention relates generally vto a processhead box III and are adapted to contact the formof making hard, denseboard, slabs or panels and ing rolls I3 and I4 respectively.particularly to such bodies which have high Sheet I6, formed by rolls I3and I4, is pa strength both wet and dry and have a small coto a suitablewet press to remove the surplus 5 emcient of expansion in the presenceof moisture. moisture. The wet press consists of belts I1 and An objectof the invention is to produce in a I8, mounted upon rolls I9, 20, 2I,22, 24 and 25. shorter time composite bodies or sheets adapted Rolls 23are for the purpose of maintaining proper for use in construction ofbuilding and for various tension on the belts I1 and I8. other uses. TheSheet I6, after having the surplus moisture i Another object of theinvention is to provide an removed by the wet press, is passed to asuitably 10 improved process for making board or sheets in constructeddryer. 'Ihe dryer may be single tier which high temperatures are usedand the body 0r, if desired, They-be multiple tier- The drier is movedalong continuously. consists of upper section 26 and lower section 21.

Another object is the production of bodies of In the upper part of thedryer is located heating l various types from nbrous vegetable materialof coils 28 while the heating 1s supplied to the lower 1s any desiredlength, width and thickness, section by heating coils 29. 'I'hetemperature of 'Ihe inventionrelates to the production of hard. thedryer iS preferably around 600 F. to 700 F. stili bodies by rst formingfrom vegetable brous 0h the Wet 0I receiving end and 300 F'.V to 450pulp stock a body, removing the surplus moisture F- 0n the discharge 01'dry end.

gd from the body, passing the body through a heater The Sheet l5 may bedivided at B after being 20 to remove the moisture, heating the body toraise discharged from the dryer. The moisture conthe temperature thereofwith comparatively light tents 0f the sheet as it comes from the dryermay pressure, applying higher temperatures, a rela.- be bone dry butfo!` aneCOnomical operation it iS tively high4 pressure for 9,relatively Short time preferred that the moisture contents be Within 25and then quickly chilling the hot pressed body. the range of 2 to 10%.2,. 'I'he last step may be omitted but it Is preferred The dl'y Sheet,Whether bone-dry or air-dry iS that it be used. I passed to a preheatingpress consisting of sec- Incarrying out the process water-proong mations3l and 32 in which are mounted heating terial and/or binders may beadded but they rolls 33 and 34. 'Ihe temperature maintained in may beomitted if desired and a good product 0bthe preheater presser should bewithin the range 30 tained, of 400 F. to 500 F., preferably about 425 F.

With the foregoing and other'objects in view Preferably OnlySUrfeeeContact DreSSure iS apthe invention consists of the novel steps andcomplied irl the preheater Presser.' The board or bination of stepshereinafter more specic'ally deproduct in the preheater has theconstituents of' 35 scribed and illustrated in the accmpanyig thevegetable material rendered substantially 35 drawing wherein is shownembodiments of the inplastievention but it is to be'understood thatchanges, One .01 more Pairs 0f large hOt Pressing rolls, variations andmodifications may be resorted to 39 and 0. are DOSitiOhed adjacent thedischarge which fall within the scope of claims hereunto end of thepreheating press.' The rolls 39 and 40 appended, are heated by anysuitable means as for instance 40 In the accompanying drawing: by steamintroduced through members 43 and 44. Figure 1 is a vertical-sectionthrough an ap- 'Ihe waste steam is withdrawn from rolls 39 and paratusshowing a view diagrammatically illusvthrough the medium of conduits 31and 38. trating such apparatus for making composition The conduits31 and38 discharge the waste heat 45 boards, sheets or bodies which includes afelting through headers 35 and 36, into the preheater 45 device, a wetpress, a high temperature dryer, a press.

heat and hot pressing device. The large pressing rolls 39 and 40 areheated In Figure 1A is a vertical section view of the from 500 F. to 575F., preferably about 550 F. pressing rolls and chilling rolls. Thevegetable material contained in the board at Referring to the drawing indetail, I0 indicates the time it reaches the large rotatable pressing ahead box for 'receiving the vegetable brous members is in a highls1Plastic condition. 'Ihe pulp, II. operatively mounted adjacent the he'ad,pressure applied by rolls 39 and 40 varies in acbox are forming rolls I3 and I4 which'pick up cordance with the kind of product desired fromthe bers and .form them into a continuous sheet. 500# per square inch to2000# per square inch.

y u Flexible mmbers I2 and I5 are secured to the Generally to obtain aproduct that has a tensile 55 strength above 6000 pounds per squareinch, a pressure of about 1000# per square inch is employed.

The pressed and hot board. 45, may bedivided into suitable lengths bymeans of cut-off member 46. In the preferred process the board asdischarged from the large hot pressing rolls is 'passed between coolingor chilling rolls. The

chilling rolls may be maintained in a cold condition by any suitablemeans. The hot pressed board which has the temperature quickly broughtdown below the plastic point of the substance contained in the vegetablematerial is of greater by mechanical means or'by a relatively light cooking process.

If desired, material from an extraneoussource such as vegetable oil ormaterial, mineral oils or material, and animal oils may be incorporatedin the product to`increase the water resistance. Hydrogenated whale oilin an amount from 1% to 5% has given excellent results and decreases thewater absorption about 50% over a product not having the oilincorporated therein. If a material from an extraneous source isincorporated in the product it is preferred that such material have thecharacter of hardening under heat and pressure.

Shouldv Whale oil be used it is generally commingled with the vegetablei'lbers while in a water suspension. The drying of the board to removesubstantially all the moisture without pressure preliminarily heattreats the oil which permits of a rapid hardening under heat andpressure. If board-like bodies are to be produced by this process, thetime for completing the board is about one-half the time required byknown processes. The strength and other qualities of the productsproduced in accordance with the process hereinbefore described are verymuchhigher than any heretofore made.

The surface of the products produced by my process is smooth, highlypolished and does not have surface pores that can be detected by theeye. The heat-hardening products of the vegetable material being pressediiow to the surface of the product and give it a high surface strengthand water resistance. 'I'he surface on the products made by my processhas great resistance to surface abrasion, in fact, substantially fourtimes the resistance of any known pressed board.

The following is one example for producing board-like bodies: Wood isreduced to pulp by the grindstone method. Three per cent of whale oil iscommingled with the pulp while in a water bath by passing the oil andpulp through a Jordan. A thick sheet is formed and the surplus moistureis removed and the sheet is passed to a high temperature dryer wheresubstantially all the moisture is removed or at least has the moistureremoved down to an air drycondition. The

dry board is then passed through the preheaterpress, the temperature inthe preheater being about 440 F. The board becomes heated throughout andbecomes qui-te plastic. The

' rollers or rotatable members compress the board very little as only.surface contactis maintained. The hot board is quickly compressed toits substantial final thickness by the large heated rotatable members.The pressed board is then quickly -chilled by cooling rolls. The sheet,board or product is in continuous motion from the time the product isformed until completed. y

If vegetable oils or mineral water-prooflng materials are incorporatedwith the pulp. they receive a preliminary heat treatment when the boardor product is dried, which permits ofquick hardening under heat andpressure. It is unnecessary when using my process to heat cure thefinished product.

It is to be understoodthat variation and modification can be resorted towhich fall within the scope of the appended claims.

It is preferred that a portion of the high temperature dryer be providedwith top rollsor rotatable members 30'. The moisture of the board at thetime the top rolls are applied usually is and should be 'about 30% orlower. The rolls 30', .smooth or iron the surfaces of the board and alsoresult in utilizing that portion of the vegetable material which can betermed water-soluble, hardening material. Such materials harden as themoisture leaves it as is the case of ordinary glue.

The board discharged from the dryer has a substantially smooth surfaceor surfaces and the water-soluble binder is set. The board dischargedfrom the dryer can be used if high strength smooth surface insulatingproducts are desired. The board or product thus produced has relativelyhigh insulating value and at the same time has higher wet and higher drystrength than any known insulating board. A Y

To obtain a very dense and rigid board, the board or product dischargedfrom the dryer is then passed to the preheater press and subjected tothe additional steps as shown by the drawing and hereinbefore described.

The boards discharged from the large heating rolls, 39 and 40, are notpermitted to materially cool until they reach the chilling rolls. Thechilling of the boards under pressure, results in setting up those partsof the vegetable material that hardenupon cooling. Thus by this method,all the natural cementing materials of the vegetable materials that actasa binder are utilized.

It is possible to use physical condensation products from an extraneoussource aswell as chemical condensation products due to the. fact ofchilling the hot pressed board. What is intended to be covered by theterm physicalcondensation products are binders and/or waterproofingmaterials that harden by cooling. By `chemical ycon-- densationproducts, it is intended to covervheat hardening binders vand/orwaterproofing.v materials.

The waste heat from the preheater press be..

withdrawn asv at C, and discharged iutoQvtlie ydryer and the waste heatfrom` the dryerniaybewithdrawn as at D and used v for heatn th""watersuspension of the vegetablei ing of the sheet or' bo`a.rd.',lf`

Board produced in accordano has higher surface resistance ,to abrasion,higher' wet strength after soaking -in water for fortywith uns' processeight hours, and vhigher dry strength than any known pressed fiberproduct.` g

Any vegetable i'lbrous material may be used in the process and it isintended to include woods of various kinds and fibers obtained fromannual plants. Whatever kind of wood vor woody material is used, it ispreferred that the major portions of the natural cementlngmaterials bein the berlzed Vmaterial when pressure is applied. What I claim is:,y 1. A process of making. board-like-bodies from raw vegetable fiberswhich includes commingling approximately 3% of whale oil with fiber in awater suspension, forming a board from the iibers, pressing the sheet toremove the surplus moisture, drying the sheet without pressure to reducethe moisture content to about 30%, thereafter ironing the surface of theboard while continuing the drying, then applying surface contactpressure at a temperature of about 400 to 460 F. to `the board having amoisture content from 2 to 10%, thereafter applying pressure of at about500 pounds per square inch to the dry board at a temperature of about500 to 575 F., and nally quickly chilling the board to lower thetemperature whereby the board is cemented together 'by natural cementingmaterial contained in the iibers.

2. A process of making board-like products from vegetable ber containingsubstantially all of the natural cernenting materials of the originalvegetable material comprising drying a wet boardto 575 F., andthereafter quickly chilling the hot board-like product under pressure'by,means of rotatable members.

3. A continuous process of making -board-like bodies which comprisesforming a board from vegetable fibers in a water suspension, pressingthe board to remove the surplus moisture, advancing the board through adryer, smoothing the surface of the board in the dryer after themoisture content has been reduced to below 30%, then heating thesubstantially dry boardwhile maintaining surface contact with the movingboard by rotatable members'at a temperature above 400 F., applying highpressure to the hot and dry board at a temperature of about 500 to 575F., and then quickly reducing the temperature of the hot pressed boardby passing the board between chilling members.

4. A process of making hard, highly waterresisting, and' denseboard-like bodies which includes commingling hydrogenated whale oil withfibers in a water suspension. passing a mixture ofb pulp and oil througha Jordan to substantially uniformly coat the fibers with oil, forming aboard, pressing the board to remove the surplus -moisture, drying theboard without pressure to reduce the moisture contents, ironing thesurfaces of the board. after the moisture contents have been reduced toabout 30% while continuing the drying, then heating the board at atemperature of about 400 F. to 500 F. with light surface ,contactpressure, and pressing the hot board ata temperature within the range of500 to 575 F. at a pressure from 500 to 2000# per square inch.

5. -A process of making hard, dense and highly water-resistantboard-like bodies fronr vegetable fibers in a water suspension,commingling a Water-proofing material with the bers, forming aboard-like body, removing the surplus moisture, drying the board withoutpressure, then smoothing the surface of the board during' drying afterthe moisture has beenreduced to about. 30%, then applying only surfacecontact pressure at a temperature Within-the range f about 400 F. to

about 500 F., thereafter applying consolidating pressure at atemperature above 500 F. and then quickly chilling the hot board underpressure..

6. A process of making board-like-products including the steps offorming. a felted vboard from vegetable iibrous material in a watersuspension, removing the surplus moisture, drying the board to reducecontents to substantially air dry condition, then heating the, board ata temperature of about 400 F. to 500 F. with only surface contactpressure to render the vegetable materialhot and plastic, thereafterapplying consolidating pressure at a temperature above 500 F., and thenquickly chilling the hot board under pressure.

7. The process of making hard and highly water-resistant board havinghigh tensile strength, including the steps of mixing a water-proofingmaterial with vegetable bers in a water bath, pressing 'a board toreduce the moisture contents, drying the board vand smoothing thesurface of the board during drying after the moisture contents have beenreduced to about but above 15%, then applying light pressure to thesubstantially dry board at a temperature of about 400 to 500 F.,applying 500 to 2000# per square inch at a. temperature above 500 F. tothe hot, dry board, and coldpressing the hot board to quickly reduce thetemperature below 212 F.

- l GEORGE Hr ELLIS.

